Dental equipment stand



DENTAL EQUIPMENT $TAND Original Filed April 5, 1959 5 Sheets-Sheei 1rps4,

Zmnentor 305E11 a/llyell,

April 10, 1945 R. C. ANGELL DENTAL EQUIPMENT STAND I Original FiledApril 5, 1959 5 Sheets-Sheet 2 Gttorueg April 10, 1945. R. c. ANGELLDENTAL EQUIPMENT STAND Original Filed April 5, 1939 5 Sheets-Sheet 3 vZinpentor Jib/9PM CAR 06]! wyzmw (Ittorneg April 10, 1945. R. Q ANGELL2,373,442

Q I I DENTAL EQUIPMENT STAND Original Filed April 5, 1939 5 Sheets-Sheet4 FlCi': 9;

i'ioezi C flizgdl, 8g 4 attorney Patented Apr. 10, 1945 DENTAL EQUIPMENTSTAND Robert 0. Angel], Prince Bay, N. Y., assignor to llhe S. S. WhiteDental ManufacturingCompany, a corporation of Pennsylvania Originalapplication April 5, 1939, Serial No. 266,174, now Patent No. 2,317,971,dated May 4, 1943. Divided-and this application April 2, 1943, SerialNo. 481,579

Claims.

This application constitutes a division from my copending applicationSerial No. 266,174, filed April 5, 1939, now Patent No. 2,317,971 datedMay 4, 1943, and is specifically directed to spray bottle warmer andwater tumbler supporting mechanism.

My invention relates particularly to that class of dental equipmentassemblages that are adapted to be located adjacent to a dentaloperating chair and arranged to support, within easy reach of theoperator, various instruments, implements, appliances and devicesemployed in the practice of dentistry, and is especially di rected toits simplified construction, easy accessibility of its enclosedmechanism, wide range of relative movement of the associated parts, andthe consequent flexibility in the use of such instruments.

The principal objects of my invention are to provide an assemblage ofdental equipment devices embodied in stand or pedestal that is' compact,pleasing in appearance, convenient to operate, readily assembled andtaken. apart and that affords a maximum degree of utilityin the practiceof the dental profession.

Other objects of my invention are to provide an equipment assemblagecomprising a standard or pedestal upon which various relativelyadjustable equipment and dental devices may be conveniently moved intorelatively different op-' erative positions about the common axis ofsaid standardor pedestal. Y

Further objects of my invention are. to provide a dental equipment standassemblage in which the frame of the supporting standard is composed ofa plurality of frame sections relatively superposed one upon another andsecured together to form a supporting skeleton standard stand assemblagehaving a bracket table rotat-.

ably supported on a swingable supporting arm which is mounted forhorizontal movement about the axis of said stand and including a framecarrying connection terminals for gas and air which are connected byflexibletubing spirally coiled about the common axis of said swingablesupporting arm and stand with suitably disposed stationary connectingterminals of gas and air conveying pipes extending upwardlythrough thestand or pedestal.

Another object of my invention is to provide a spray bottle warming unitand X-ray illuminator swivelingly mounted at the outer end of aswingable supporting arm which is in turn pivotally mounted on thebracket table arm and arranged'to swing about the axis of the brackettable, whereby said spray bottle warming unit Specifically stated, theform of my invention as hereinafter described, comprehends an equipmentstand comprising a pedestal of generally cylindrical formation having aflanged base and a dome-like upper extremity from which pro-' J'ects acylindriform engine mechanism mounting, and'h'aving horizontally swingable arms disposed at relatively different levels and respectivelycarrying a bracket table and a cuspidor. Said pedestal is preferablyformed of a plurality of separable frame sections each designed toprovide specifically for its intended purpose and assembled one uponanother in a prescribed order and secured together with their respectiveaxes coincident with the axis of the thus assembled standard whichprovides a supporting frame standard that may be enclosed by a pluralityof readily removable and replaceable substantially semicylindricalcasing sections preferably of sheet material assembled to form thecylindriform pedestal structure. The swingable arms for the brackettable and cuspidor are provided with suitably formed casing sections ofsheet material which have their inner semicylindrical ends in coincidentalinement with the cylindrical wall; formed by the adjacent casingsections and serve to form therewith the complete shell or closure forthe above described assembled supporting fragmentary vertical sectionalelevational view of the equipment stand pedestal showing the base andupper portion with the intermediate region broken away for convenienceof illustration, and including the inner end portion of the brackettable supporting arm; Fig. 2 is a plan view of said equipment standpedestal including the bracket table. its supporting arm and embodying asecondary or forearm swingable horizontally about the axis of thebracket table and carrying at its free end a combined spray bottlewarmer and X- ray illuminator rotatably mounted thereon, about avertical axis at the free end thereof; Fig. 3 is a front elevationalview of the structure shown in Fig. 2; Fig. 4 is a horizontal sectionalview of the secondary or forearm which supports the spray bottle heaterand illustrates the means for previces and parts, to be hereinafterdescribed, may be mounted for convenient utilization.

The base section I is provided with the enlarged base flange 6 adaptedto rest upon the floor and to be secured thereto by the bolts 1 extendedthrough'suitably spaced apertures 8, andhas four upwardly extending legs9,"terminating in a substantially octagonal perforated elevated plate orplatform 10, said platform I being provided with two diametricallyopposite outwardly projecting lugs 46 each having a vertical notch orslot I! cut or otherwise formed therein, and indented for a purpose tobe hereinafter described.

superposed upon the base section I is the main body section 2 whichcomprises the relatively spaced parallel plane side wall I!) and 20reventing entanglement of the electric cords lead ing therethrough tosaid spray bottle heater and X-ray illuminator when said arm is swungupon its axis of rotation; Fig. 5 is a fragmentary vertical sectionalview taken through the electric cord directing guide on the line 5-5 inFig. 4, a portion being shown in elevation for convenience ofillustration; Fig. 6 is a perspective view of the electric corddirecting guide which is shown in plan view in Fig. 4; Fig. 7 is aperspective view of the electric cord supporting guide to which saidelectric cord is attached and guided thereby into the spray bottleheater; Fig. 8 i aperspective View of the clip bywhich said electriccord is attached to said supporting guide; Fig. 9 is a front Ielevational view of the spray bottle heater and X-ray illuminator with afragment of the swingable arm upon which they are mounted, a portion ofthe forward .wall of said illuminator being broken away to betterillustrate the interior parts; Fig. 10 is a transverse centralyerticalsectional view of the spray bottleheater and X-ray illuminator assembly,the upper portion of said spray bottle heater being shown in elevationfor simplification; Fig. 11 is a fragmentary plan sectional view of theassembled structure shown in Fig. 10 taken on the line li--ll in Fig. 10and showing a fragment of the spray bottle heater frame; Fig. 2 is aside elevational view of the spray bottle, of which there are two shownin Fig. 9; Fig. 13 is a vertical longitudinal sectional view of thespray bottle heater shown in Figs. 2. 3 and 9 taken axially through thespray bottle receptacle; Fig. 14 is a plan view of the supporting frameof the spray bottle heater shown mounted for rotation upon a fragment ofthe outer end of the secondary or forearm of the bracket table arm; Fig.15 is a horizontal sectional view of the spray bottle heater taken onthe line I5-l5 in Fig. 13; Fig. 16 is a transverse vertical sectionalview taken axially through the water glass receptacle, the X-rayilluminator attached thereto being shown in elevation; Fig. 17 is anenlarged vertical transverse sectional view of the accessory brackettable arm brake and its cooperative brake ring shown in Fig. 1, taken onthe line l1 l1 in Fig. 2; and Fig. 18 is a perspective view of one ofthe similar opposed clamp blocks which retain the opposed friction brakepads, which are shown in Fig. 17.

In said figures the frame forming the supporting standard. comprises thebase section L the main body section 2, the combined water niche andcuspidor section 3, accessory table-arm section 4 and the dome or motorsection 5, all being assembled by building one upon the other about aunitary common vertical axis in the order named to provide a skeletonstandard structure upon which the various operating appliances, de-

spectively terminating at their lower ends in the annular horizontallyextended flange 2| and being joined vertically by the transverse wall 23which is inset from the edges of said wall [9 and 20 but preferablydisposed nearer to the rear edges of said walls.

The transverse wall 23 terminates short of the annular flange 2| andmerges into the horizontally extended shelf 25 projecting rearwardlyfrom the lower end of said transverse wall 23 and having its curved freeedge joining the free vertically disposed rear edges of the side wallsI9 and 20.

. The main body section 2 is supported on the base section I and has thefour feet 3| which de-. pend from the under surface of the annularflange 21 in relatively spaced relation and rest upon the plateor-platform ll) of base section 1 to which the main body section 2 isrigidly secured by the bolts 32, shown in 'Fig. l.

The combined niche and cuspidor mounting section 3 is superposed uponthe main body section 2 and comprises a unitary structure having thefour posts or standards 40 terminating upwardly in the top plate or cap4| unitary therewith and having a central aperture 42 and flange 43, andproviding a circular horizontal track 44 and a cylindrical verticaltrack 45 for supporting bearing structure to be later described.

The accessory table-armsection 4 is superposed upon the water niche andcuspidor mounting section 3, and, as best, shown in Fig. 1, comprises ahollow circular hub 54 having a depending inner rim bead 55 extendingint a correspondingly formed recess or rabbet 56 in thecap 4| of thewater niche and cuspidor mounting section 3 to which said section 4 issecured by bolts 51, one of which is shown in the plane of section inFig. 1.

Said accessory table-arm section 4 is provided with the horizontalflange 58 disposed intermediate of its axial length and having adepending annular projection 59 providing a flat horizontal undersurface afiording a circular roller bearing track 60 in suitably opposedspaced relation to the circular track 44 on thecap 4|. The upwardlyextending portion of said hub 54 is externally re-,

cessed to provide the shoulder 6| arranged to support the annular shelf62, and terminates upwardly in the inner rim bead 63.

The motor section 5 is superposed upon the accessory table-arm section 4and serves as a crownpiece or dome for the skeleton standard structurethus assembled. Said motor section 5 comprises the annular floor havingthe lower edge of. its inner rim rabbeted to. receive the upwardlyextending inner rim projection or head 63 on the circular hub 54, and tobe secured thereto by the bolts 66, and from which floor 65 rise thediametrically opposite U-shaped standards 61 re spectively curvinginwardly at their upper extremities and merging into the annular head69.

The accessory table arm 10 is adapted to oscillatably swing horizontallyabout the unitary axis of the standard structure, upon which it is sup-.ported, and its frame II comprises at the free end an annular mountingI3 upon which an accessory table I2 may be conveniently supported, asshown in Figs. 2 and 3. I

The inner end of the frame II comprises the circular bearing mounting15, the rim of which embraces the hub 54 in concentric relation theretoand serves to provide a substantially annular inner terminal structureencircling said hub 54:.

As best illustrated in Fig. 1, the table arm II! is supported forhorizontal movement into different positions convenient to the operator,by the three supporting rollers 81 respectively mounted on the headedtrunnionsv 90, which project inwardly from the bearing mounting l5.

The rollers that serve best to directly carry the weight of theprojecting arm I and the parts supported thereon,consequently aredisposed relatively close to each other upon opposite sides of avertical plane passing through the axes of the annular ends of theaccessory supporting arm frame, and roll upon the track 44, while theroller 'I'I which serves to balance the arm rolls -upon theopposed'superjacent track 60, and is preferably disposed with its axisof rotation substantially coincident with said vertical plane.

As shown in section in Fig. 1, the roller 11, which is typical of thethree supporting rollers,

is annular in form and is provided with a ball race I8 in its innercylindrical surface, in opposed relation to the ball race IS in theoutward sur face of the ball race. annulus 85., and relatively revolvesabout said annulus on the bearing balls 8| which are arranged totraverse the opposed ball races 18 and I9.

' In order to retain the accessory table arm ID in axial registry withthe supporting standard structure or pedestal, it is provided with thehorizontally disposed equally spaced rollers 82 there being three suchrollers arranged to traverse the cylindrical track 45, the roller 82,shown in the plane of section in Fig. 1, being disposed with its aXis ofrotation in a vertical plane coincident with the axis of the supportingroller TI and journalled to rotate on the headed shaft 85 which, asshown in Fig. 1, extends through an aperture in the boss 86 ontheinwardly projecting rib 81 of thebearing mounting I5, and which isengaged in stationary relation therewith by the nut 89 threaded thereon.

Thus it will be seen that the accessory table arm I0 may freely revolveabout the axis of the standard structure and be moved into any desiredposition convenient to the operator. However, it has been founddesirable to adju'stably restrict its too free movement and to preventits over running when its position is changed, and therefore a brakedevice is employed which, as shown. in 17, comprises the annular disk-90 which is rotatably engaged between the water niche and cuspidormounting section 3. and the accessory table arm section 4, and which isirictionallyengaged between the jaws ill and 92- of the brake devicecomprising the opposed jaw plates 93, and 9.4. respectively having theopposed lips or ridges 95 and 96 upon which they may slightly rock.

Said jaw plates are respectively provided with pockets 9 9 and I 00 inwhich friction pads HH- and I02 are held in opposed relation infrictional engagement with the upper and under sur faces of said disk 90respectively, said pads IfiI nd I02 being engaged with said disk in nydesired degree. of yielding frictional contact with said disk 90, seeFig. 1'7, by the adjusting screw I03, which extends through the apertureI05 in the jaw plate 94 and into threaded engagement with the jaw plate93. Said adjusting screw W3 is encircled by the spiral spring Hi6disposed between its head I01 and. the jaw plate 94, and has the reducedend I09 extended into the aperture III] in the accessory table armsection 4, whereby it is retained and prevented from radial displacementin the pocket III in the cap ll of the water niche and cuspidor section3.

The accessory table arm I0 is normally locked in engagement with saidannular disk 95, so that it may be moved only by considerable manualpressure, the amount of which depending upon the frictional pressure ofthe friction pads I-lll and IE2 incident to the adjustment of saidadjusting screw. I03, but said arm may be auto-.

matically released from such locked engagement to freely move about itsaxis of rotation.

As shown best in Figs. 2 and 3, the hollow spray bottle warmersupporting arm, 36, which is mounted to revolve about the axis of theaccessory table I2 on the table mounting bearing -I3I, which issupported on the ledge I39 in the annular mounting I3 of the. accessorytable arm "It, as shown in Fig. 3, said arm I and table I2 beingarranged toindependently revolve upon the free end of saidaccessorytable arm, and jointly movable about the axis of the supportingstandard or pedestal.

As shown in Figs. 2; 3 and 9, said water warmer supporting arm I316 isprovided at its free end with the annular mounting I40 upon which thespray bottle and water tumbler warmer I ll is mounted to revolve. inFig. 13 is provided with the receptacles I42, I43 and I44, respectivelyarranged to receive the removable and replaceable spray bottles I45 andM6 and the water tumbler I 4'I, shown in Fig. 9,

- the spray bottle illustrated in side elevation in Fig. 12 beingtypical of both of those shown in.

Fig, 9, and comprising the connection nipple M8, the swivel coupling M9and the nozzle I50.

The body I51 of the spray bottle and water tumbler warmer MI is providedwith the electric heating element I52 having .the terminals I53 and I56and secured thereto-by the'screws I55, see Fig, 13. Said body is mountedupon the base frame I56 from whichi-t is insulated by the interposeddiaphragm I51 of non-conducting material, and secured by the screws I66extended through the lugs I58 of said base frame I56, said diaphragmI51; being independently attached to the lugs I59 of the body I5I by thescrews I-6,I-.,

The spray bottle warmer body I5I:, as shown in Figs. 13; 15 and 16, isprovided with the shell or casing I52 between which and said body thejacket I65 of heat insulating material, preferably insheet form, isinterposed, and said shell or casing I62 extends downwardly and aiiordsa depending apron. which also embraces the base frame I56.

The spray bottle warmer is arranged to independently revolve on itssupporting arm"I3B which is provided at its outer free endwith theinwardly extending rim- IGG providing the bear ing seat I51 upon whichthe. centrally disposed generally circular spider, I69 of the base frameI56- rests for relative rotation, being held in axial; position, thereonby the annular retainer Iil'Il which rotatably bears. ag inst: the.under faceof' Said warmer I4I', as shown theinset rabbet I1I -intheinner edge of said rim I66, and said retainer I19 is secured to theframe spider I69 by the screws I12.

As shown in Figs. 13, 14 and 16, the base frame I56 is provided with thebottom closure supporting lugs I13 and I14 projecting inwardly and towhich the bottom closure plates I15 and I16 may be secured by the screwsI11 and I18 to enclose the chamber I19 included between said closureplates and said diaphragm I51, see Fig. 13.

The supply of electric current to the heating element I52 may bemanually controlled to turn it on or off as may be desired, and it isalso automatically controlled by thermostatically actuated mechanism tomaintain a relatively uniform desired temperature.

Said electric current may be introduced into the spray bottle warmer bythe electrical conductors I89 and I8I which lead from suitably providedconnections and extend through the pedestal, accessory table arm andspray bottle arm I36, as shown in Figs. 14 and 16, and which extendspirally in the semicircular free end of said arm I36 and terminate atthe terminals I82 and I83 in the terminal plates I84 and I85, on theterminal block of insulation material I86 which is secured to the spiderframe I69 by the screws I81, see Fig. 14.

The electric circuit through the heating element I 52 may be made orbroken by mechanism including the rocker post I86 which extendsvertically through the diaphragm I51 and which is mounted to rock in thebearing bracket I89 which, as shown in Fig. 15, is secured to the underside of said diaphragm I51 and secured by the screws I99 extendedtherethrough.

Referring again to Fig. 15, the rocker post I36 is provided beneath thediaphragm with the spring contact finger I9I which carries the con tactI92 in opposed relation to the contact I93 mounted in stationaryrelation on the mounting bracket I94 also secured to the underside ofsaid diaphragm I51 by the screw I95 extended therethrough, whichmounting bracket I94 also carries the magnet I96 in opposed relation tothe magnet keeper or bridge I91, which is carried by said contact fingerI9I as above described.

With further reference to Fig. 15, the rocker post I88 is provided withthelever arm I98 which is connected by the link I99 to the outer end ofthe bimetallic thermostatic coiled spring or strip 299 which is limitedin forward movement by the guide post 29I and is spirally coiled aboutthe rock-shaft 292 journaled in the bearing bracket 293 secured to theunderside of the diaphragm I51 by the screws 295.

Said rock-shaft 292, as shown in Fig. 16, carries at its lower end thehubbed disk 296 which is secured thereto by the screw 291, and whichcarries the rocker-arm or lever 299 having its inner circular endenlarged and encircling the hub of said disk 296 and secured thereto soas to move therewith by the screw 2I9. The outer circular end 2 I2 ofsaid lever 299 is extended into the rectangular void or recess 2I3, bestshown in Fig. 13, in the rack-bar 215, having the upwardly projectingrackpteeth 2I6.

With reference to Figs. 13, 15 and 16, the rackbar 2I5 is arranged toslide longitudinally on the shelf type supporting bracket 2" which issecured to the diaphragm I51 by the screws H9 and depends therefrom, asshown in Figs. 1 and 16. Said bracket 2I1 has its lower horizontal wingor shelf 229, see Fig. 15, provided with the longitudinally extendingapertures 22I and 222 through which the shanks of the screws 223 and225, threadedly engaged in said rackbar2I5, extend with their respectiveheads 226 and 221 underlying and loosely "engaging the under surface ofsaid horizontal shelf 229 of the bracket 2H, and maintaining therack-bar 2I5 in sliding contact with the upper surface of said wing orshelf 229.

The teeth 2I6 of the rack-bar 2I5 are interengaged with the teeth of thepinion 239 on the inner end of the shaft 23I which is mounted to rotatein the bearing 232 depending from the diaphragm I51 and secured theretoby the screws 233. Said shaft 23I extends rearwardly through the casingI62 and isprovided with the controlling knob 235 by which said shaft 23Imay be rotated to shift the rackbar 2I5 and thereby rotate therock-shaft 292 to wind or unwind the coiled thermometal strip 299. Apointer 236 arranged to move with said knob 235 indicates the positionof the rack-bar 2I5.

Turning of the controlling knob 235 in a clockwise direction effectswinding up of the coiled strip 299 which tends to draw the lever arm I98and the contact spring finger I9I toward the right hand with respect toFig. 15 and to effect breaking of the electric contact between thecontacts I92 and I93. Turning of the controlling knob 235 in ananticlockwise direction eifects unwinding of the coiled strip 299 toproduce movement of the contacts I92 and I93 together to complete theelectric circuit therethrough to energize the heating element I52.

The coiled strip 299 is disposed in the chamber 239 with the heatingelement I52 and is arranged to automatically effect actuation of thelever arm I 98 and the spring contact finger I9I to separate thecontacts I92 and I93 and thereby break the electric circuit in which theheating element is included when the temperature in said chamber 239rises to a degree predetermined by the position of said rack-bar 2 I5and variably controlled by the knob 235.

The terminal I53 of the heating element I52 may be connected throughsuitable wiring with the terminal 249 which connects through the contactfinger I9I, contacts I92 andl93 with the terminal 24I of the terminalplate I84. The terminal I54 of said heating element I52 may be connectedthrough suitable wiring with the terminal 243 of the terminal plate I85.As above upon the forward bar of the base frame I59 of the spray bottlewarmer and is secured thereto by the screws 255 which extend upwardlythrough the countersunk apertures 256 in said base frame I56.

Said frame 252 supports the illuminator casing comprising the top wall259, the bottom wall 269. both of which curvedly merge into the forwardwall 262, and the end walls 263 and 265. Said forward wall 262 isprovided with the window opening 266 which is surrounded by the windowframe 261, the inner margin 269 of which overlaps said window opening266, .and is secured to said forward wall by the screws 219.

As shown in Figs. 9, l and 11, the-window opening 266 is provided withthe pane of. glass 212 which is retained in the window opening 266 bythe brackets 21-3 disposed oppositely and substantially in alinementwith the lower edge of said glass pane 212 and respectively extendingfrom the end walls 263 and 265. and provided with the outwardlyprojecting lugs 216 extending beneath the glass pane 212 and. serving tosupport it, and the outwardly projecting lugs 21'! which extend over thelateral edges-of said glass pane to maintainit in proper registry withsaid window opening 266. 1 f

As shown in Fig. 10, the glass pane 212 is also retained by the brackets279 similarly disposed oppositely in alinement with the upper edgethereof, said brackets 219 being similar to the brackets 213 and beingprovided with the outwardly projecting lugs 289 extending over thetopedge of the glas pane 272 and the lugs 28I extending over the lateraledges of said glass pane As shown in Figs. 10 and 11, the brackets 213and 219, which may preferably be secured by spot welding to the sidewalls 263 and 255 of the X-ray illuminator casing, are respectivelyprovided with the spring clip 282, see Fig. ll,which are arranged tobear against the inner surface of the glass pane 212 to maintain it inthe window open-' ing 266 in contact with the inner overlapping marginof the window frame 261. The lower bar of the window frame 26! has theupturned extension 233 providing a convenient support for holding a filmbefore the glass pane 272. I ,7

As shown in Figs. 9, 10 and 11, the X-ray illuminator is provided withthe reflector comprising the complementary concave reflective sections285 and 286 respectively having oppositely directed outwardly extendedflanges 289 and 290, andthe inwardly extended relatively parallelfianges29! and 292. The flange 289 is engaged with the brackets 279 by thescrews 293 and the flange 290 is secured to the brackets 213 bythescrews295, so that, as will be observed, the reflector comprising thecomplementary concave sections, forming -a reflector structure having asubstantially tangential parabolic contour, brackets 213 and 219. U I IAs best shown in Fig. 10, the flanges 29! and 292 of the reflectorsection are secured to the bar 296 of insulation material, preferablyBakelite by the screws 23'! to which bar the lamp supporting spring clipterminals 298 and 239 are attached by is supported by said the screws300 and .3! which extend through' suitably provided apertures in saidbar 236 in threaded engagement with the terminal plates 302 and 303respectively.

The spring clip terminal 296 and 299 are conveniently spaced toreceivethe terminal collars 305 and 306 of the tube type electric lamp301 which is provided with a backing of refractory material and which issupported by said spring clip terminals 298 and 299 in suchpredetermined relation to the parabolic reflector surface as to directrelatively parallel light rays through the glass pane 212.

The terminal plates 302 and 303 are provided with the screw terminals309 and 3I0, the terminal 309 being connected by the electric wire 3I2with the terminal 3I3 on the terminal plate I05 in the base of the spraybottle warmer, and the terminal 3 I 0 being connected by the electricwire 3l5 with the terminal 3I6 on the terminal plate I 85 in the base ofsaid spray bottle warmer. However, the wire 3l5 is connected through therheostat switch 3.! 'Iwhichis arranged to be'actuated by the controllingknob 3I9. I 1

As shown inFig. '4, the .wires I and. I8l' are included in the electriccord 320 which enters the spray bottle warmer supporting arm I36 throughthe tubular elbow fitting guid 322, and curves forwardly toward the freeend of said arm into a free return 10010323 from which it extendsrearwardlyinto the loop 325 permanently restricted by the'clamp band326, and from which loop 325 said cord 320 extends forward through thesupporting and directing clip 32! from where it extends in the loop323upwardly through the bushing 330 in the free circular end 33I of thebushing supporting bracket 332 into the base I56 of the spray bottlewarmer where said wires I80'and I8I are attached to their respectiveterminals,see Fig. 14. i I v Referring againto Fig. 4, the electric cord320 rests upon the floor 333 which has that portion which is disposedbetween the elbow fitting guide 322 and the loop 323 backed by theguide-335 formed ofa strip of sheet spring material that is secured inany manner, such as by the rivets 336, to the elbow fitting guides 322:and extends curvedly forwardly therefrom, forming a backing for saidelectric cord 320 and tending to prevent buckling thereof, andterminating in a preferably circular loop 33l arranged to slide upon theinner surface of therear wall 339 of the spray bottle warmer arm I36. vi

With further reference to Fig. 4, it has been found desirable when thefree end of the spray bottle. warmer arm I36'is moved forwardly from itsnormalposition with respect to. the accessory table arm I10 and theelectric cord 320 has been relatively shifted to the position shown indot and-dash lines in said figure, that the spring backing guide 335 bemaintained flattened in its medial region, and for this reason theinwardly curved region of the rear wall 339 is providedlower end toprovide a bearing 34'! for said elbow 322, and said restrictedendportion is provided with screw threads 34.9 with which the nut 350 isthreadedly engaged.

As illustrated in Fig. '7, the bracket 332, which is shown inperspectivev therein, has its inner end portion 352 slightly depressedand terminates in the enlarged circular attachment 353 having theaperture 355 through which the screw 356 extends, see Fig. 4, to engageit with the lug 35! extending inwardly from the forward wall 360 of thespray bottle warmer supporting arm I36. Said screw 356 also engages theclip 32'! which, as shown in Fig. 8, has the circular attachment 362provided with the aperture 363 through which said screw extends toattach it in superposed relation to the attachment 353 of the bracket332.

Referring to Fig. 4, it will be obvious that the spring backing strip335 tends to maintain the electric cord 320 in such curved relation,irrespective of the position of the spray bottle warmer arm with respectto the accessory table supporting arm upon which it is arranged torevolve, and that when said electric cord 320 moves from its retractedposition, shown in dot-and-dash lines, to its extended position, shownin full lines, it will be so reinforced and supported asto prevent itsbuckling or fouling, or otherwise tending to jam and interfere with thefree movementof said spraybottle warmer arm.

My invention has many advantages over similar devices as heretoforeconstructed for supporting parts and accessories in convenient positionfor use by the professional operator, and affords not only easy accessfor use, but facilitates access for adjustment, repairs and replacementof all of said parts, and is particularly adapted for eliminating partsthat may not be desired by individual operators and the substitution oraddition of parts and accessories that may be desired, by otheroperators, and, in this particular respect, it is possessed ofindividual flexibility and consequent superiority.

I do not desire to limit my invention to the precise details ofconstruction and arrangement as herein set forth,,as it is obvious thatvarious modifications may be made therein without departing from theessential features of my invention as defined in the appended claims.

Having thus described my invention, I claim:

1. A dental equipment assemblage comprising a supporting standard, arelatively movable supporting frameproviding a radially extended armarranged to swing about the axis of said standard as a center, anaccessory table supported on said arm and arranged to independentlyrotate thereon, a secondary supporting arm mounted on the tablesupporting arm and movable horizontally about the axis of said table, anaccessory device mounted for-independent rotation on the free end ofsaid secondary arm, and including electrically energized elementsconnected with a source of electric energy by an electric conductorextending through said supporting arms and having a free loop and acooperative restricted loop whereby to facilitate extension andretraction of said conductor, and a spring backing guide arranged tomaintain said looped conductor properly posed.

2. An equipment assemblage comprising a mounting, a hollow supportingarm mounted on said mounting arranged to swing on a vertical axis andhaving a floor provided with an opening and marginal walls embracingsaid floor, a conductor entering said arm through its supported endregion and leaving said arm at its free end region and includingintermediate loops preferably resting on said floor and slidable thereonto afford extension and contraction incident to variation of thedistances between the entrance and exit points of said conductor, and aspring backing guide arranged to maintain said conductor properly posedto prevent its fouling when said arm is swung on its mounting.

' 3. An equipment assemblage comprising a mounting, a hollow supportingarm mounted on said mounting arranged to swing on a vertical axis andhaving a floor provided with an opening and marginal walls embracingsaid floor and having an internal abutment; a conductor entering saidarm through'its supported end region and leaving said arm at its freeend region and includin intermediate loops preferably resting on saidfloor and slidable thereon to afiord extension and contraction incidentto variation of the distance between the entrance and exit points ofsaid conductor; and a spring backing guide limited in its movement bysaid abutment and arranged to maintain said conductor properly posed toprevent its fouling when said arm is swung on its mounting.

4. An equipment assemblage comprising a mounting, a hollow supportingarm mounted on said mounting arranged to swing on a vertical axi andhaving a floor provided with an openin and marginal walls embracing saidfloor, a conductor entering said arm through its supported end regionand leaving said arm at its free end region, and including intermediateloops preferably resting on said floor and slidable thereon to affordextension and contraction incident to variation of the distance betweenthe entrance and exit points of said conductor; and a spring backingguide provided with a curved bight serving as a slide shoe, arranged tomaintain said conductor properly posed to prevent its fouling when saidarm is swung on its mounting.

5. An equipment assemblage comprising a mounting, a hollow supportingarm mounted on said mounting arranged to swing on a vertical axis andhaving a floor provided with an opening and marginal walls embracingsaid floor; a conductor entering said arm through its supported endregion and leaving said arm at its free end region and includingintermediate loops preferably resting on said floor and slidable thereonto afiord extension and contraction incident to variation of thedistance between the entrance and exit points of said conductor; anda-spring backing guide anchored at its inner end and provided with acurved bight at its free end serving as a slide shoe arranged tomaintain said conductor properly posed to prevent its fouling When saidarm is swung on its mounting.

ROBERT C. ANGELL.

